Cardiac rhythm management systems are useful for electrically stimulating a patient's heart to treat various cardiac arrhythmias. A proposed method of electrically stimulating the heart includes stimulating the His bundle located proximate to the apex of the triangle of Koch in the right atrium of the heart. By directly stimulating the bundle of His, both the right and left ventricles can be physiologically activated, potentially avoiding pacing induced dyssynchrony present with right ventricular apex pacing. There is a continuing need for improved His bundle lead designs and assemblies.